Clamp



Nov. 28, E944, M. A. BRELSFORD CLAMP Filed Oct. 30, 9 5

Smaentor BRELSFEIRD (Ittomeg Patented Nov. 28, 1944 CLAMP, Harlin A. -Brelsford, Haddon Heights, N. 1., as-

signor to RadioCorporation of America, a cor-,

. poration of Delaware Application October 30, 1943, Serial No. 508,423 I 4 Claims. (01148 .346) p The invention covered herein may be manufactured and used by or forthe Government of the United States for any governmental purpose "without payment to me orassignslof any royalty thereon. v

This invention relates to clamps and particularly to improvements in so-called tube clamps.

In many mobile electrical installations, and especially in those subject to shock and tremors of external origin, it is customary to secure certain replaceable units such, for, example, as vacuum tubes, coil forms, capacitors, etc. to a chassis orother base by means of adjustable clamps.

The usual tube clamp comprises a strip of metal aflixed to the support and adapted to encircle the base of the tube, or. other unit, and is provided at its opposite ends with complementary lugs or ears through which the clamping force'is applied to the strip as'by means of. a screw and nut. The

principal objection to such clamps is that the adjusting mechanism (e. g. the screw and nut) is I accessible only from the sideof the installation. Hence, if, as is usually the case, the tube and other units are arranged in closely spaced rows the clamps in the center and rear rows are relatively inaccessible so long as the units in the other rows remain in position.

Accordingly, the principal object of the present invention is to provide a simple, inexpensive and trouble-free clamp and one wherein the adjusting mechanism is accessible from the top (01' bottom) of the set wherebyreplacement of the clamped device may be effected without disturbing the set-up of nearby units.

The foregoing and other objects and advantages are achieved, in accordance with the invention, by the combination with a spring metal strip or like part, adapted to encircle the unit to be clamped, of cam means operatively connecting the ends of said strip and an actuating member (say, a screw), which extends in a direction substan tially perpendicular to the plane of the surface upon which the assembly is mounted, for applying a clamping force to said unit through said cam means and spring metal strip.

Certain preferred embodiments of the invention are shownin the accompanying drawing, wherein:

Figure 1 is an elevational view of a vacuum tube and a clamp therefor constructedand arranged in accordance with the principle of the invention and showing the direction and manner of applying the clamping force,

Figure 2 is a plan view of the assembly shown in Figure 1, and

Figure 3 is a fragmentary view in perspective showing another embodiment of the invention. In the drawing, wherein like reference characters designate the'same or corresponding parts in all figures, l designates' a panel or chassis of a radio or other apparatus and 3 designates adevice, say 'a vacuum tube having a cylindrical" socket or base 5- and which is supported on or above the panel by aclamp comprising a spring metal strip 'l-which encircles the base 5 of the device; As shownin Fig. 3, the spring metal strip "Imay simply reston the panel I or, as shown in Figs. 1 and'2, it maybe supported above the panel as on legs 9a, 9?), etc. which are welded or otherwis aflixed to the outer surface of the said strip.

In this latter case, the feet of the rear legs and 9d may be secured to the panel I as by screws llcand l Id, respectively; the front legs 9a and 9b being free to slide on the surface of the panel so that the spring strip 1 maybe flexed when a clamping force, supplied by a screw 13 and nut I5, is applied thereto or removed therefrom. The,

nut IE will be understood to be welded or otherwise affixed to the panel I.

The screw l3 extends from a point beneath the panel I upwardly between the outwardly turned ends of the spring metal strip 1 and is provided at its upper end with a cam comprising a rigid, inverted V-shape member I! having a flattened central portion llf against which the head l3a of the screw I3 is adapted to bear. A projection 13b on the screw beneath the flattened central portion of the cam I I1 causes the cam to follow the screw when it is being unscrewed.

In the embodiment of the invention shown in Figs. 1 and 2 the outwardly extending portions of the flexible metalstrip 1 are provided with cam surfaces 1a and 1b similar to the ones on the screw actuated cam I1. surface sections of the strip 1, adjacent to its opposite ends, slant downwardly and outwardly with respect to a line'drawn perpendicular to the base between the said end portions, and at an anglecorresponding substantially to the inclined inner surfacesof the inverted V-shape cam l'l.

Thus, as the screw I 3 is turned by means of a screw driver l9 inserted from above, the cam surfaces of the part If! ride on the inclined surfaces Ia and lb on the clamping strip 1 and move it into or out of clamping engagement with the base 5 as determined by the direction. in which it is rotated. As previously mentioned, the movement of the spring metal strip 1 is in no wise inhibited by the legs 9a and 9b since they are That is to say, the outernot attached to the panel I but are mounted to permit of slidable movement thereon.

It-is not essential that faces 1a and 1b on the spring metal strip 1 have the same angle of tilt as those on the cam H. In fact, as shown in Fig. 3, the said parts la and lb may comprise parallel faces perpendicular to the plane of the panel I. In this case, the inclined faces of the cam l1 'gbear only against the :upper edges of these parallel faces when the cam is actuated by the screw 13. While this would appear to cause the upper edge of the'strip to cant inwardly, this tendency is overcome when the strip engages the surface of the socket 5 or vice. I v

Irrespective of the angle at which the faces "Ia other clamped deand. lb are inclined with respect to the cam I! it is preferable to bend the extremities of the flexible strip 1 outwardly in opposite directions as indicated at Ix, 111 to prevent the cam from :lmdes red wi tias or latera sa rament as w 1131 tu nedng; i i 15 s arent that the xne siate he adclam ed device ma be, ef ected without distant: n h set-up o othernear v malts What is claimedis: a a 1i ,1- Apparatus e th t p described aa pristag,

' in combination, .a l ase, a c amping membe acmrisin flexible stripadem d in he a m o esi 91- the nsta a ed whereby :aeplaeement 9 said base and to be circumferentially disposed about the object to be clamped, cam means operatively connecting the ends of said flexible strip, and means extending in a direction perpendicular to said base between said ends of said flexible strip and accessible from a point along the said perpendicular for adjusting said cam means, whereby to apply a clamping force to said object through said flexible strip.

2. A clamp comprising the combination with-a flexible strip having a body portion adapted to encircle the object to be clamped and having -;,outwardly extending oppositely located spacedmeans comp ising a screw dis osed between s d nd porti ns and in con act the central por on o said M, forae nating said cam.

.4. The invention as set forth claim :3 and wherein thesu a es of said nd portions of said strip are inclined at substantially the ame angle as the incl ned urliaces of said veshape 10am.

' HARM-N A. BRELSFQRD. 

